[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at f81bae9 [flang][msvc] Do not use gcc/clang command line options for msvc.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   f81bae9..039fb7f  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 039fb7f68af9f89f8116d769a9e4cae458baca38.
CMake Error at CMakeLists.txt:3 (cmake_minimum_required):
  CMake 3.13.4 or higher is required.  You are running version 3.7.1


-- Configuring incomplete, errors occurred!